This invention relates to a method of treating vascular thrombosis in warm-blooded animals, employing an ethyl- or vinylbenzene as the active antithrombotic agent.
A thrombus generally is defined as an obstruction, formed from components of blood, within the vascular system. When a thrombus is either free-floating in the blood stream or has been removed by the blood stream to a new location, it is referred to as an embolus. Thrombosis, which refers to the formation, development, or presence of a thrombus, is responsible for a variety of disorders which generally are termed thromboembolic diseases. Such diseases include phlebothrombosis, thrombophlebitis, pulmonary embolism, retinal thrombosis, myocardial infarction, and cerebal infarction, among others. More generally, such diseases can be considered to result from a vascular thrombosis, i. e., a thrombus within the vascular system of the body.
The chemoprophylactic or chemotherapeutic management of thromboembolic diseases generally involves compounds which fall into one of three categories: (1) platelet aggregation inhibitors, (2) anticoagulants, and (3) fibrinolytic agents. The chemotherapeutic use of fibrinolytic agents is based upon the fact that fibrin frequently forms the primary structural support of a thrombus. Dissolution of the fibrin should result in lysis of the thrombus, with restoration of blood flow. Anticoagulants and platelet aggregation inhibitors, on the other hand, generally are employed prophylactically. Anticoagulants are more effective in the treatment of venous thrombosis than arterial thrombosis. The successful prophylaxis of arterial thrombosis must deal with the etiologic role of the platelet. The value of platelet function inhibitors in venous thrombosis, on the other hand, will be reflected by the extent to which platelets are involved in the formation of those thrombi. In any event, there are within the circulatory system regions of stasis in which fibrin formation would be virtually the sole factor in thrombosis, and other regions of high hemodynamic activity where the platelet nidus alone could block the vessel.
Consequently, the search for effective new platelet aggregation inhibitors continues to be an important research activity.
Certain ethyl- and vinylbenzenes, defined hereinafter, now have been discovered to be active antithrombotic agents, even though many of such compounds are known.